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Li D.,Beijing Jiaotong University | Zhang L.,Beijing Municipal Commission of Urban Planning | Sun Y.,Beijing Municipal Commission of Transport
Proceedings - 2013 5th Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2013 | Year: 2013

Traffic surveillance systems that use cameras are an important tool for controlling pedestrian crowds in subway stations. Large stations need many cameras which cause difficulty for traffic-control operators who need to react quickly when an accident takes place at a specific location. This paper reports on a new technology based on computer vision for use in a pedestrian crowd estimation and safety detection system. The system first collects data from video cameras and instantly converts the data to gray-brightness images frame by frame. Then the outline of each pedestrian in each image is extracted using Sobel filter convolution. Parameters of the processed images are obtained for each frame. The functional relationship between pedestrian density and image parameters (such as bin30) is set up. An alert system is developed based on this proposed method. The paper presents a test-case of the Lama Temple interchange station of the Beijing subway. The density and fundamental diagram of the flow of pedestrians is tested and compared with the same data collected manually. Results show that this methodology is effective, fast, and practical for use. © 2013 IEEE. Source

Liu X.,Beijing Municipal Commission of Transport | Chen J.,Beijing Municipal Commission of Transport | Liu Z.,Beijing Jiaotong University | Chen H.,University of Leeds | Ge Y.,Beijing Municipal Commission of Transport
Proceedings of the Conference on Traffic and Transportation Studies, ICTTS | Year: 2010

Beijing is a city with a history of about 3,000 years. In the past several decades, pursuing to be industrialized used to be a main goal of the city which caused more and more serious pollution problems. Since the late of 1990s, actions have been taken to deal with the air pollution in Beijing in order to enhance living level of its residents. However, countermeasures taken firstly were almost on the adjustment of development routine of industry. Until recent years, especially approaching the 2008 Olympic Games, complicated schemes on green transport was concretely carried out. It was not only aiming for a currently clean air, but also a future sustainable development of transport and urbanization. Among the actions taken on green transport, there are exploration of low emission vehicles, priority to public transport, cycling and walking improvement and intelligent information techniques application. This paper summarizes these action schemes and what's on now in Beijing. © 2010 ASCE. Source

Yang S.,Beijing Normal University | Yin G.,Beijing Normal University | Shi X.,National Marine Hazard Mitigation Service | Liu H.,Beijing Transportation Information Center | Zou Y.,Beijing Municipal Commission of Transport
International Journal of Disaster Risk Science | Year: 2016

Cities are centers of socioeconomic activities, and transport networks carry cargoes and passengers from one city to another. However, transport networks are influenced by meteorological hazards, such as rainstorms, hurricanes, and fog. Adverse weather impacts can easily spread over a network. Existing models evaluating such impacts usually neglect the transdisciplinary nature of approaches for dealing with this problem. In this article, a mesoscopic mathematical model is proposed to quantitatively assess the adverse impact of rainstorms on a regional transport network in northern China by measuring the reduction in traffic volume. The model considers four factors: direct and secondary impacts of rainstorms, interdependency between network components, and recovery abilities of cities. We selected the Beijing-Tianjin-Hebei region as the case study area to verify our model. Socioeconomic, precipitation, and traffic volume data in this area were used for model calibration and validation. The case study highlights the potential of the proposed model for rapid disaster loss assessment and risk reduction planning. © 2016, The Author(s). Source

Cheng H.,Beijing University of Technology | Yang X.-K.,Beijing University of Technology | Liu X.-M.,Beijing Municipal Commission of Transport
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2013

The purpose of traffic congestion pricing is to reassign the traffic volume for the whole road network. The problem of determining optimum toll is stated by game theory. The interaction between road authority and road users can be considered as a two-level game model with N+1 players. The two-level game model of congestion pricing is proposed and the game equilibrium is analyzed in the paper by introducing a virtual road network as an example to figure out the optimum toll. The objective of congestion pricing game is to find system-optimal tolls and user-optimal traffic flows. Source

Li F.,Chinese Research Institute of Highway | Zhou Y.,Beijing Municipal Commission of Transport | Li T.,Chinese Research Institute of Highway | Zeng W.,Chinese Research Institute of Highway | Wang X.,No. 56 Oxygen Road
International Journal of Pavement Research and Technology | Year: 2015

Low temperature performance of hot-applied bituminous crack sealant is a key factor which influences the effect of asphalt pavement crack filling and sealing. In order to describe the constitutive stress-strain relationship at low temperature, experimental tests of extension and stress relaxation of crack sealants, are presented in this paper. The generalized Maxwell model is chosen for curve-fitting to determine the material model. Comparison of fitted curve and experimental results proves that the generalized Maxwell model in Prony series is well suited for describing the experiment process. Moreover, finite element analysis method with material model defined by the generalized Maxwell model in Prony series is introduced for numerical solution of tension and stress-relaxation of crack sealants. By comparing the results of the numerical analysis and the tests, the conclusion can be made that the tension and the stress-relaxation of crack sealants may be accurately depicted by the generalized Maxwell model. © Chinese Society of Pavement Engineering. Source

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